This Aug. 10, 2013 file photo shows a rare mountain yellow-legged frog in an alpine lake in Kings Canyon National Park, in California’s Sierra Nevada. Hundreds of California’s endangered yellow-legged frogs have been airlifted from their native Sierra Nevada lakes to big city zoos for booster shots and a chance at beating extinction from disease back in the wild. (AP Photo/Brian Melley, File)
Read more »This Aug. 10, 2013 file photo shows a rare mountain yellow-legged frog in an alpine lake in Kings Canyon National Park, in California’s Sierra Nevada. Hundreds of California’s endangered yellow-legged frogs have been airlifted from their native Sierra Nevada lakes to big city zoos for booster shots and a chance at beating extinction from disease back in the wild. (AP Photo/Brian Melley, File)